ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/libecb/ecb.h
Revision: 1.12
Committed: Thu May 26 18:17:45 2011 UTC (13 years ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.11: +12 -2 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 /*
2 * libecb
3 *
4 * Copyright (©) 2009-2011 Marc Alexander Lehmann
5 * Copyright (©) 2011 Emanuele Giaquinta
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without modifica-
9 * tion, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright notice,
12 * this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
19 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
20 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
21 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
22 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
26 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27 * OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #ifndef ECB_H
31 #define ECB_H
32
33 #include <inttypes.h>
34
35 /* many compilers define _GNUC_ to some versions but then only implement
36 * what their idiot authors think are the "more important" extensions,
37 * causing enourmous grief for some better fake benchmark numbers or so.
38 * we try to detect these and simply assume they are not gcc - if they have
39 * an issue with that they should have done it right in the first place.
40 */
41 #if defined(__INTEL_COMPILER) || defined(__SUNPRO_C) || defined(__llvm__)
42 # define ECB_GCC_VERSION(major,minor) 0
43 #else
44 # define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
45 #endif
46
47 #ifndef __cplusplus
48 # if __STDC_VERSION__ >= 199901L
49 # define ECB_INLINE inline
50 typedef _Bool ecb_bool;
51 # else
52 # define ECB_INLINE inline /* yeah! */
53 typedef int ecb_bool;
54 # endif
55 #endif
56
57 #define ECB_CONCAT_(a, b) a ## b
58 #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
59 #define ECB_STRINGIFY_(a) # a
60 #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
61
62 #define ECB_HEADER_INLINE static ECB_INLINE
63
64 #if ECB_GCC_VERSION(3,1)
65 # define ecb_attribute(attrlist) __attribute__(attrlist)
66 # define ecb_is_constant(c) __builtin_constant_p (c)
67 # define ecb_expect(expr,value) __builtin_expect ((expr),(value))
68 # define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
69 #else
70 # define ecb_attribute(attrlist)
71 # define ecb_is_constant(c) 0
72 # define ecb_expect(expr,value) (expr)
73 # define ecb_prefetch(addr,rw,locality)
74 #endif
75
76 /* no emulation for ecb_decltype */
77 #if ECB_GCC_VERSION(4,5)
78 # define ecb_decltype(x) __decltype(x)
79 #elif ECB_GCC_VERSION(3,0)
80 # define ecb_decltype(x) typeof(x)
81 #endif
82
83 #define ecb_noinline ecb_attribute ((noinline))
84 #define ecb_noreturn ecb_attribute ((noreturn))
85 #define ecb_unused ecb_attribute ((unused))
86 #define ecb_const ecb_attribute ((const))
87 #define ecb_pure ecb_attribute ((pure))
88 #define ecb_hot ecb_attribute ((hot)) /* 4.3 */
89 #define ecb_cold ecb_attribute ((cold)) /* 4.3 */
90
91 #if ECB_GCC_VERSION(4,5)
92 # define ecb_unreachable() __builtin_unreachable ()
93 #else
94 /* this seems to work fine, but gcc always emits a warning for it :/ */
95 ECB_HEADER_INLINE void ecb_unreachable () ecb_attribute ((noreturn));
96 ECB_HEADER_INLINE void ecb_unreachable () { }
97 #endif
98
99 /* put into ifs if you are very sure that the expression */
100 /* is mostly true or mosty false. note that these return */
101 /* booleans, not the expression. */
102 #define ecb_unlikely(expr) ecb_expect (!!(expr), 0)
103 #define ecb_likely(expr) ecb_expect (!!(expr), 1)
104
105 /* try to tell the compiler that some condition is definitely true */
106 #define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
107
108 /* count trailing zero bits and count # of one bits */
109 #if ECB_GCC_VERSION(3,4)
110 ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) { return __builtin_ctz (x); }
111 ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) { return __builtin_popcount (x); }
112 #else
113 ECB_HEADER_INLINE
114 ecb_ctz32 (uint32_t x) ecb_const
115 {
116 int r = 0;
117
118 x &= -x; /* this isolates the lowest bit */
119
120 if (x & 0xaaaaaaaa) r += 1;
121 if (x & 0xcccccccc) r += 2;
122 if (x & 0xf0f0f0f0) r += 4;
123 if (x & 0xff00ff00) r += 8;
124 if (x & 0xffff0000) r += 16;
125
126 return r;
127 }
128
129 ECB_HEADER_INLINE
130 ecb_popcount32 (uint32_t x) ecb_const
131 {
132 x -= (x >> 1) & 0x55555555;
133 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
134 x = ((x >> 4) + x) & 0x0f0f0f0f;
135 x *= 0x01010101;
136
137 return x >> 24;
138 }
139 #endif
140
141 ECB_HEADER_INLINE unsigned char
142 ecb_byteorder_helper () ecb_const
143 {
144 const uint32_t u = 0x11223344;
145 return *(unsigned char *)&u;
146 }
147
148 ECB_HEADER_INLINE ecb_bool ecb_big_endian () ecb_const { return ecb_byteorder_helper () == 0x11; };
149 ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const { return ecb_byteorder_helper () == 0x44; };
150
151 #if ecb_cplusplus_does_not_suck
152 // does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
153 template<typename T, int N>
154 static inline int ecb_array_length (const T (&arr)[N])
155 {
156 return N;
157 }
158 #else
159 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
160 #endif
161
162 ECB_INLINE uint32_t
163 ecb_rotr32 (uint32_t x, unsigned int count)
164 {
165 return (x << (32 - count)) | (x >> count);
166 }
167
168 ECB_INLINE uint32_t
169 ecb_rotl32 (uint32_t x, unsigned int count)
170 {
171 return (x >> (32 - count)) | (x << count);
172 }
173
174 #if ECB_GCC_VERSION(4,3)
175 ECB_GCC_VERSION uint32_t ecb_bswap32 (uint32_t x) { return __builtin_bswap32 (x); }
176 #else
177 ECB_GCC_VERSION uint32_t
178 ecb_bswap32 (uint32_t x)
179 {
180 return (x >> 24)
181 | ((x >> 8) & 0x0000ff00)
182 | ((x << 8) & 0x00ff0000)
183 | (x << 24);
184 }
185 #endif
186
187 #endif
188